1. Field of the Invention
The disclosure relates to a light source apparatus and a projector having the light source apparatus.
2. Description of the Related Art
Recently, a time divisional type projector has become popular. The time divisional type projector emits lights of a plurality of wavelengths and forms images by modulating the emitted lights of the plurality of wavelengths sequentially, and then projects the formed images. As a light source apparatus used for the time divisional type projector, for example, there is known a light source apparatus having a light source that outputs a white light, and a rotating wheel to which a plurality of color filters are attached. According to such light source apparatus, the light source emits the white light to the rotating wheel which rotates at constant speed, and thereby emitting lights of a plurality of wavelengths (such as blue, green and red lights) in a time divisional manner.
Further, there is also proposed a light source apparatus including a light source that outputs a light of a single wavelength, such as a laser diode, and a rotating wheel having phosphor layers instead of color filters. According to such light source apparatus, the light source emits the light of a single wavelength to the rotating wheel which rotates at constant speed, and thereby emitting lights of a plurality of wavelengths in a time divisional manner. For example, it is possible to convert wavelength of a blue light from a laser diode into that of a green or red light by using phosphors. In such light source apparatuses, as described in JP 2011-133782 A, there is proposed a method to enlarge an approximately oval shape of a light which is emitted from a laser light source and condensed onto the phosphors by installing the laser light source rotated around its optical axis, and thereby making uniform brightness for projecting.
As described in JP 2012-215633 A, there is proposed a method to change a position of the light condensed position of each laser light source on the phosphor by varying distances of the plurality of laser light sources and distances of collimator lenses located at the output side of the laser light sources, and thereby exciting the phosphors with a low light intensity.
According to the light source apparatus described in JP 2011-133782 A, the rotating direction of each laser diode needs to be adjusted in the case of rotating the laser diode around the optical axis. Further, since a light emitted from each laser light source is condensed onto the same position, the light intensity at the light condensed point may be so high that the emission efficiency of phosphor is reduced. According to the light source apparatus described in JP 2012-215633, a position of a light condensed position of each laser light source can be changed. However, as a diameter of the light condensed position formed by a parallel light from the collimator lens is small, the light intensity of a parallel light from the collimator lens is high, so that the emission efficiency of phosphor may be reduced.